Epilepsy A-Z: Common and Rare Types of Epilepsy (Part 1)

Sep 21, 2016 | Trends

Epilepsy is a chronic neurological disorder defined by recurrent seizures. Previously, we discussed what seizures are including how they manifest and progress. We briefly examined the broad types of epilepsy based on where in the brain they started and whether or not they spread to other parts of the brain.

There are at least 40 different types of epilepsy. Each type of epilepsy can come with a different seizure types. Each person’s epilepsy is unique to them, comprising different specific triggers, aetiologies, seizure types and severity among other characteristics. Different forms of epilepsy can be grouped into categories. These 4 categories describe the electrical activity pattern that occurs in the brain to induces a seizure. Diagnosis is usually made by an epilepsy specialist using a combination of descriptions of the seizures, an EEG, an MRI and family history. Here, we’ll dive deeper into these categories. This article will be more specific than our previous article. For a broader focus, we recommend reading that article first.

  1. Focal Epilepsy: abnormal activity in the brain that is limited to one area.

Benign Rolandic Epilepsy With Centro-Temporal Spikes (BECTS)

Alternative names Features Include Triggers

Benign Rolandic Epilepsy of Childhood (BREC) or Rolandic Epilepsy.

Twitching, numbness, or tingling of the child’s face or tongue. Symptoms can interfere with speech and may cause drooling.

Sleep deprivation.

Prevalence Genetics Brain Area Affected Prognosis

Accounts for about 15% of all epilepsies in children.

Possible link to chromosome 15q14.

Rolandic part which controls movement.

Seizures usually disappear 2-4 years after they first begin and stop on their own by age 15.

 

Benign Occipital Epilepsy

Alternative names Features Include Triggers

Benign focal epilepsy with occipital paroxysms.

Panayiotopoulos type: vomiting, looking to one side, incontinence, rhythmic muscle contractions on one or both sides of the body and others.

Gastaut type: visual hallucinations, headaches, blindness, convulsions and other occipital symptoms.

Sudden changes in lighting levels.

Prevalence Genetics Brain Area Affected Prognosis

~2% to 7% of benign childhood focal seizures

Suspected but no confirmed genes thus far.

Occipital lobe, the visual processing center of the brain. Other parts may also be involved.

Half of patients will remit within 2 to 4 years from onset.

 

Frontal Lobe Epilepsy

Alternative names Features Include Triggers

FLE.

There are several subtypes of FLE. There are no symptoms until the seizures spread to other parts of the brain. Symptoms may include responsiveness issues, speech problems, abnormal body posturing and repetitive movements commonly while the person is sleeping.

Sleep deprivation, missing meals, stress, alcohol consumption or withdrawal, dehydration, hormonal changes.

Prevalence Genetics Brain Area Affected Prognosis

Represents 20-30% of partial seizures and is the second most common type of epilepsy.

Often induced by an insult to the brain. Autosomal dominant nocturnal frontal lobe epilepsy is genetic.

The frontal lobe which is concerned with learning, working memory, behavior and attention.

Not available.

 

Parietal Lobe Epilepsy

Alternative names Features Include Triggers

PLE.

Paraesthesia, disorientation, visual hallucinations, the “Jacksonian march” (symtomps move down the body), vertigo and somatic illusions among others. There are several subtypes of PLE.

Sleep deprivation, stress, alcohol.

Prevalence Genetics Brain Area Affected Prognosis

Relatively rare. Accounts for ~5% of all epilepsy cases.

Familial PLE is associated with DEPDC5 mutations.

The parietal lobe which plays a role in processing sensory information.

Manageable with treatment. Some cases warrant surgical intervention.

 

Temporal Lobe Epilepsy

Alternative names Features Include Triggers

TLE.

Memory impairment, auras (autonomic, psychic, somatosensory), motionless staring, can evolve into a tonic-clonic seizure.

Sleep deprivation, missing meals, stress, alcohol consumption or withdrawal, dehydration, illicit drug use, diet.

Prevalence Genetics Brain Area Affected Prognosis

The most common partial epilepsy accounting for 60% of all seizures.

Polygenic.

Temporal lobe responsible for hearing, listening, language and speech processing.

Manageable with treatment. Some cases warrant surgical intervention.

Although we’ve only touched on some of the types of epilepsy here, there are some general takeaways:

  1. Epilepsy is a complex and diverse spectrum of disorders.
  2. Epilepsy symptoms are dictated by the brain regions that are affected.
  3. Seizures are more commonly when the body’s “defenses” are lower such as during sleep, in times of physical and emotional stress, as a result of low blood sugar or dehydration or if symptoms are not managed well using the appropriate therapies.
  4. There is a genetic component although this is better understood in some forms of the disorder than others.
  5. Some forms of epilepsy have higher incidence resolution than others so individual with certain forms of epilepsy may grow out of them.
  6. Epilepsy can affect many parts of the brain leading to a wide range of symptoms.

In our next article, we will cover Generalized Epilepsy, Progressive Myoclonic Syndromes and Reflex Epilepsy. It is our hope that by increasing awareness and reducing misinformation on epilepsy, the stigma attached to the diagnosis will be reduced. Do you know someone affected by epilepsy? What did you learn from this article that you didn’t know before?

Let us know if you would like to see us cover any particular topics in the future and email or post your questions!


Article by Olwen Reina. Contact Olwen at olwen@tempobioscience.com.

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